In general, medical imaging systems, such as computed tomography systems, comprise at least one radiation detector that detects radiation from a source, e.g., the patient. One of the patient and/or the source are rotated around an object to be examined, e.g. a patient, within an angular range.
The angular range extends from the start angle of the system to the end angle of the system. To reduce artifacts in reconstructed images, the angular range is desirably at least 180° for parallel-beam geometry, or 180° plus the fan-angle for fan-beam geometry to satisfy the data completeness condition.
If an acquisition range is less than the angular range of the system, i.e. a limited-angle acquisition range, then the object will have unsampled angular regions and consequently, the reconstructed images may have reconstruction artifacts.